The invention relates to a method for handling, in particular for repairing of replacing, busbars on wind power plants. The invention further relates to a method for handling, in particular for repairing or replacing, bus bars on wind power plants.
In the transmission of the power generated in a generator in the region of the top of a tower of a wind power plant into a substation arranged at the base of the wind power plant, a differentiation is basically made between two methods: In the first method, the power is transmitted via a cable from the generator to the substation. In the second method, the power transmission takes place by means of busbars. Here, for bridging the distance between the base region and the head of the tower of the wind power plant, usually a plurality of busbars are used, connected or respectively screwed to one another, which have, for example, a typical length of approximately 3 m.
The tower of a wind power plant generally consists of several tower segments arranged on top of one another, which are respectively constructed in a sleeve shape. During the manufacture of the wind power plant, in the second method for power transmission the busbars are already fixed to the inner wall of the respective tower segment during the manufacture of the tower segments, so that the busbars arranged or respectively fixed inside a tower segment form a busbar subregion. After the placing of the individual tower segments on one another in situ, the individual busbar subregions of the tower segments are electrically contacted or respectively coupled with one another by means of connection bars. The individual busbars of a busbar subregion are elastically fixed or respectively suspended within the tower segment by means of a fixing device, having a bracket, via an elastomer element, serving as intermediate element, in a bolt, which in turn is anchored in the wall of the tower segment.
On mounting and especially during the operation of the wind power plant, in the course of time, for example as a result of different thermal expansions between the tower of the wind power plant, consisting of steel, and the busbars, usually consisting of aluminium, mechanical stresses occur within a busbar subregion and between the individual busbar regions, which are to be balanced out through the elastic suspension of the busbars by the elastomer elements. Furthermore, as a result of the elastic suspension of the busbars via the elastomer elements, the weights of the individual busbars are partially transferred to the busbars respectively arranged beneath.
Owing to the special geometric construction of the busbars, it is not possible, without the risk of damage to individual busbars, to remove an individual busbar from a busbar subregion due to a necessary repair or a necessary replacement. Firstly, the connection bar arranged above the affected busbar subregion to the next busbar subregion must be disconnected. Only then can a replacement take place of the busbar which is to be repaired or respectively replaced by removing all busbars of the affected busbar subregion above the busbar which is to be repaired or respectively replaced. On re-mounting the busbars of a busbar subregion, the procedures are repeated in reverse sequence. Owing to the elastic suspension of the busbars and the mentioned stresses between the busbars and between the busbar subregions, on re-mounting of the busbars additional stresses are introduced into the busbar interconnection formed from the individual busbar subregions, which can previously damage the busbar interconnection. Moreover, during the repair or replacement, the busbars of the busbar above that which is to be repaired or respectively replaced are partially stressed by the weight of busbars arranged above, so that these settle by a certain distance and therefore if applicable the elastomers of the relevant busbars can be previously damaged, which if applicable can not be detected visually.